I think the Daily Mail may have exaggerated the numbers: The DC Fire Department reported 60,000 - 70,000 people....

Regardless, the crowd was HUGE and the event was epic.

Obama's response was:
"'THEY CAN'T STOP US': OBAMA WARNS HIS HEALTH CARE MUST PASS..."

Pants On Fire:

http://www.politifact.com/truth-o-meter/statements/2009/sep/14/blog-posting/blogger-claim-photo-shows-millions-tea-party-prote/

So we have one blogger of unknown veracity posting a incorrect picture. Let's just settle on the fact that it was a very large crowd, one that the politicians ought to be concerned about if they want to be reelected.

You might want to check this clip, also:

http://clipmarks.com/clipmark/9FA9A720-914C-4B85-ADA5-799F8017F91D/